package com.hmdp.utils;


import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
//全局唯一ID
public class RedisIdWorker {

    //开始时间戳
    private static final long BEGIN_TIMESTAMP = 160995200L;

    //序列化位数
    private static final int COUNT_BITS = 32;
    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    //创建订单id
    public long nextId(String keyPrefix){
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long currentTime = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = currentTime - BEGIN_TIMESTAMP;
        //2.生成序列化
        //2.1获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //2.2redis自增长
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //3.拼接并返回

        //时间戳向左移动32位，再拼接序列化
        return timestamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2024, 4, 4, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second=" + second);
    }

}
